Telegraph signal code translator



Jan. 25, 1949.

Filed Deo. 9, 1943 M4N s/ Tren a'ls rfi/su E. F. WATSON TELEGRAPH SIGNALGODE TRANSLATOR 3 Sheets-Sheet 1 /NVE/vro? E. F WATSON 5yd@ a. cue?ATTORNEY Jan. 25, 1949. E. F. WATSON 2,459,904

TELEGRAPH SIGNAL GODE TRANSLATOR Filed Dec. 9, 1943 I5 Sheets-Sheet 2Jan. 25, 194.9. E F, WATSON v 2,459,904-

TELEGRAPH SIGNAL CODE TRANSLATOR Filed Dec. 9, 1945 3 Sheets-Sheet 5/m/E/v Tof? -E .F WATSO/V Patented Jan. 25, 1949 TELEGRAPH SIGNAL CODETRANSLATOR Edward F. Watson, Larchmont, N. Y., assignor to BellTelephone Laboratories, Incorporated, New York, N. Y., a corporation ofNew York Application December 9, 1943, Serial No. 513,501

This invention relates to improvements in telegraph transmissionsystems. More specically this invention relates to the translation ofmultielement permutation telegraph signals, in accordance with one code,into multielement permutation telegraph signals in accordance with adifferent code.

Where a first telegraph system arranged for the transmission of signalsin accordance with a iirst code is connected to a second telegraphsystem arranged for the transmission of signals in accordance with asecond and different code, it is necessary to translate the signalcombinations in accordance with the first code into signal combinationsin accordance with the second code before they can be transmitted overthe second system. The invention herein performs such translationautomatically, by electromechanical means. If the second system isreconnected to a third system employing the original code it isnecessary to retranslate the signals into the original code. Theinvention herein performs such retranslation also automatically byelectro-mechanical means.

In the invention herein a long non-loaded submarine cable system,designed for the transmission of the relatively slow three-conditionpermutation code telegraph signals or cable code signals, as they areknown, and equipped at one end with a transmitter connected to a sourceof such signals and at the other end with a receiver arranged to receivesuch signals is used as a link between two relatively fast rive-elementtwocondition permutation telegraph code signal systems. Ordinarily thecable is connected to its cable code tape transmitter and its cable codereceiver. When signals originating in the veelement system are to betransmitted, a switch associated with the live-element system isoperated.Y This disconnects the cable transmitter from its normal sourceof signal supply and connects it to the iive-element system. Then aspecial multielement code signal which is generated automatically isimpressed on the cable transmitter and transmitted to the distant end ofthe cable. In response to this the distant end of the cable is switchedso that instead of being connected to its regular cable code receiver itis connected to a receiving retranslator. After the signal codelcombination which performs the switching has been transmitted thefive-element twocondition signals generated by the transmittingmechanism associated with the five-element system are changed in atransmitting translator into 13 Claims. (Cl. 178--26) four-elementthree-condition signals and impressed through a signal transmitter onthe cable. At the distant end the four-element signals are directed tothe receiving retranslator. Here the four-element signals are changedinto the original live-element signals.

When transmission from the five-element system has ended, a secondspecial multielement code signal which is generated automatically istransmitted to transfer the distant receiving end of the cable back toits regular code receiver.

The invention may be understood from the following description when readwith reference to the associated drawings in which:

Fig. 1 shows the five-element system and the transmitting translatorwhich translates the veelement signals into four-element signals;

Fig. 2 shows the cable code system including the tape transmitter, therelay transmitter, the cable, the cable code receiver, the transmittingswitching mechanism which switches the cable relay transmitter from thecable code transmitter of Fig. 2 to the five-element system of Fig. 1and the receiving switching mechanism which switches the receiving endof the cable between the cable code receiver of Fig. 2 and the four tofive-element retranslating receiver of Fig. 3;

Fig. 3 shows the four to five-element retranslating receiver;

Fig. 4 is a table showing codes used in explaining the invention; and

Fig. 5 is a diagram showing the manner in which Figs. 1, 2 and 3 shouldbe arranged to form an operative system.

Refer to Fig. 2. All of the apparatus indicated in this figure with theexception of the transmitting switching mechanism is well known in thecable telegraph art and it will not therefore be describedin detail,except insofar as it is necessary to an understanding of the codetranslating and retranslating arrangement of the invention herein.

The cable code tape transmitter 20| may be of the general automaticcable code type shown in Patent 1,517,110, T. F. Foley, November 25,1924, modied as shown in Fig. 2 herein. The regenerative repeater 2 I9in Fig. 2 may be of the type disclosed in Fig. 3 of Patent 1,827,460, F.G. Creed et al., October 13, 1931. The six pulse selectors 25|) and 210in Fig. 2 may be of the type disclosed in Patent 1,868,703, R. G.Griffith, July 26, 1932. It is understood, however, that the circuits ofthe present invention are not limited to one with cooperating apparatusin accordance with the spe- Vtact 224, winding of relay 2G53 andresistance 2 fic embodiments or foregoing patents but will function sfactorly with other cable code transmitters, regenerators and pulseselectors.

The cable transfer relay 23S is normally in the released conditionindicated to connect cable code tape transmitter 253i to the cable relaytransmitter comprising relays 2S and In Fig. 2 the cable code tapetransmitter, which is Well known in the art, is shown enclosed in arectangle 26E. The three-condition code is perforated in a tape 2li2 andthe tape is red by the well-known tape feed mechanism indicated by arectangle 2&3, over the code element sensing pins 204 and 235. When aparticular signal element is represented by a perforation the tape thecorresponding pin is admitted through the perforation to close itsassociated Contact. When a particular signal element is represented byan unperforated element in the tape neither of the two sensing pins isadmitted and their associated Contacts remain open. Contact 223 undercontrol of rotatable curbing and transmitting caro 222. For an interval,equal to one-fourth the period of rotation of cani 22S, during whichinterval the tape is feeding and the pins may change their positions inaccordance with the perforations, contact 223 is open as the cam fo1-lower engages the depressed periphery of 229. After the pins arepositioned the cam ich lower is raised and contact 223 is closed. Itwill be made apparent below that during the interval while contact 223is open both relays 238 and 25? are in the released condition. Thisapplies ground to the cable for a short interval between signalelementsto discharge the cable. This is known in the art as curbing.

The armatures of the cable transmitting relays 208 and 239 are biased tothe positions indicated by the effect of current flowing from bat- .tery2in through resistance 2| I, bottom winding of Vrelay 263, bottomWinding of relay 293 and resistance 2|2 to ground. When neither onerofcontacts 205 and .297 is closed the armatures loi relays 268 and 269remain in the positions cated. For this condition a circuit be tracedfrom ground through Contact 253, armature of relay 209, contact ZIE,armature oi relay 23B and through conductor 2l? which extends throughcable 2| 8. The ground when transmitted during the proper interval for asignal element controls the regenerative repeater 2|3 in awell-knownrmanner to impress a corresponding signal element on cablecode receiver 22 i. When ground is connected to conductor 2|? during thecurbing interval the cable is dischargedA e well-known manner.

If contact 228 is closed a circuit may be traced from ground throughbattery 222, lcontact 2..-3, sensing pin 28e, contact Zilli. resistance24-2, con Q to ground, actuating the armature of relay to the left toengage contact 2M. A circuit may then be traced from battery 223 throughContact 2M, armature of relay 292 and contact 2|5 to conductor 2 l? fromwhere it extends over path through regenerative repeater 2|3 whichimpresses a corresponding signal on receiver 22 i.

If contact 20? is closed a circuit may be traced from battery 222through contact 223. sensing pin 235, Contact 201, resistance 242,contact 223. top winding of relay 268 and resistance 22? to ground,actuating the armature oi yrelay 225 to the left to engage contact 2|6,which connects positive battery 228 through contactlili to conductor 2H,from where it extendsover a path 4 heretofore traced. Thus a signalelement which is impressed on the submarine cable may be of any one ofthree conditions, namely, po ve bf terr, negative battery or ground.Successive si? nal elements in accordance with the cable code are usedto dene each character.

Normally, as mentioned above, the three-ccnclition cable code capetransmit ci is connested to the three-condition cable transmittingrelays 253 and il. Relay 23% is in the released condition and green lamp23E is lighted ov r au obvious circuit through contact 232 or rel 23@ toindicate that tape transmitter 23 is con nected to the cable.

The circuits are arranged so w is any message to be transmitted iroelement, two-condition system of i, a in Fig. 1 is closed to operaterelay Tins connects the cable code tape trcnsinitt from the relaytransmitter compril and 26S and connects the rive-selen.A

l to the relay transmitter.

The relay transmitter comprising; and 20S which is arranged to generateth dition signals, always remain connected th cable. When signalsgenerated in the riva-eleinent system are to be transmitted, the cablerelay transmitter is iirst switched sc as to be connected to the systemof Fig. 1. Then since at the distant cable terminal the cable .isnormally connected to the cable code receiver 252i it is necessary todisconnect receiver 22 and con-- nect the receiver to the receivingretranslator per Fig. 3. This is done automatically by transmitting aspecial train or signal elements which ates a switching device at thedistant receiving end of the cable to connect the cable to theretranslator per Fig. 3. After this has been accomplished transmissionfrom Fig. may proceed. But since the signals originally generated ip A'system per'Fig. l are iive-ele1nent twoeond signals it is necessary totranslate them into 'fourelement three-condition signals berore they are.impressed on the relay transmitter` conirrising L t cic y relays 208and Zilli. After the translated are transmitted over the cable anddirected into the retranslator receiver per Fig. 3, they areretranslatedr in the apparatus of Fig. 3 to their original form andtransmittedover a rive-element system connected to the retranslator. Themanner in which the foregoing is performed will now bev described indetail.

Refer now to Figs. 1, 2 and 3. Normally relay m3, Fig. l, is in thereleased condition. Contact I4 is closed. Relay |5 is thus operated overan obvious circuit through contact H4. Contact HE is thusv open andground is disconnected from start magnet Hl. Switch |31), which is open,is first closed connecting power supply I3! to motor |32. Motor |32rotates driving shaft |33. Worm gear, |35 rigidly connected to thedriven motor shaft, spur gear |36 rigidly secured to distributor shaft|22 and distributor shaft |22 are coupled to driving shaft |33 throughfriction clutch |34. Cams |2I, |2, and rotatable arm |31 of thevfour-element transmitting distributor |38 are rigidly secured to shaft|22. The driven portion of the mechanism is prevented from rotating bythe right-hand end oi lever ||8 which is interposed in the path ofraised shoulder H2B on the periphery of cam |2| under the influence ofspring H9 which is attached to the right-hand end of the lever. Shaft|22 is normally stopped in s ucha position that continuous conductingring |39 of distributor |38 is connected through brushes |40 and 14| todistributor segment 3. Cam |24 is in the position indicated. Contact 123is closed. Relay |25 is operated as shown from battery supplied throughcontact |23. The armature of relay 126 is actuated to the right to closecontact |21 under the influence of the flow of biasing current throughthe bottom winding of relay |26 over an obvious circuit.

When signals generated in the ve-element system are to be transmitted,start key is operated. A circuit may then be traced from battery throughresistance |02, winding of relay |03, tape lever contact |04, switchconductor |10, and the winding of relay 230, Fig. 2, to ground,operating relay 230. It is pointed out that tape lever |04 is controlledby tape |01. When there is suicient slack in tape |01, due to anaccumulation of punched tape, lever |09 is lowered and contact 104 isclosed. When tape |01 is taut lever |09 is raised and contact |04 isopened to stop the operation of the transmitter distributor. Thismechanism is well known in the art. It is disclosed in Patent No.2,055,567, E. F. Watson, Sept. 20, 1936.

The operation of relay 230 opens contacts 232,

224 and 225 and closes -contacts 236, 233, 234 and 235. The opening ofcontacts 224 and 225 disconnects the cable code tape transmitter 201from the transmitting relays 208 and 209. The closing of contacts 234and 235 connects the operating windings of relays 208 and 209 toconductors 112 and I |3 which connect the cable relay transmitter to thefive-element transmitting system. The opening of contact 232extinguishes lamp 23|. The closing of contact 236 establishes a circuitfrom battery through contact 236, resistance 231, and the winding ofrelay 238 to ground, operating relay 238. Contact 243 closes. Thisestablishes a circuit from battery through contact 249 of key 24|, lamp242, contact 243 and the winding of relay 238 to ground. This locksrelay 238 under control of key 241 and lights red lamp 242 as anindication that the cable relay transmitter comprising relays 208 and209 is connected to the five-element system. While relay 238 was.

released no battery was supplied through contact 239 to a magnet controlof the tape feed mechanism 203 of transmitter 20|. The closing ofContact 239 connects battery to the magnet of tape feed mechanism 203and the feeding of tape through transmitter 201 stops immediately. Therotation of transmitting and curbing cam 229 continues. Cam 229 inaddition to controlling the length of a signal impulse transmitted overthe cable and controlling curbing cooperates in the performance ofanother function, viz., to time the signals sent from the transmitter ofFig. 1 including the transmission of a train of impulses over the cable2|8 to switch the receiving end of the lcable from the cable codereceiver 22| to the receiving retranslator per Fig. 3. The manner inwhich this is performed will now be described.

It has been explained that whenever the cable relay transmitter isseized yby the five-element system, per Fig. 1, a special train ofimpulses is transmitted over cable 218 to switch the receiving end ofthe cable from the cable code receiver 22| to the receiving retranslatorper Fig. 3. This is done automatically in response to the seizure of thetransmitting end of the cable by the operation of start switch |01. Whenrelay |03 is operated upon the closure of switch and contact ||4 isopened, battery is disconnected through conm cam 229 closes contact tact|14 from the winding of relay ||5 and relay 15 starts to release tooperate start magnet ||1 and set the transmitting distributor |38 inoperation. Relay |15 however is a slow-to-release relay. During theinterval while relay 1|5 is releasing, and before distributor |38 is setin operation, a train of at least six positive impulses is impressed, ina manner to be described hereunder, through cable 218 on the six-pulseselector 250 to perform the switching function.

When the path through the top winding ci relay 209 is transferred iromcontact 22:1: to 2342, the top winding of relay E33 is deenergized aseach of the parallel branches connecte to conductor i12 in Fig. lextends to an open circuit at this time. The armature of relay tiereioreremains in engagement with contee 'BES under the influence of itsbiasing winding while the six switching pulses are bei. g transmitted.When 3, with relay 230 0ptra-ced from battery 222 erated, a circuit mayce through contact contact 233, conductor lll, top winding of relayinner solid conducting ring |39 of distributor i323, conducting brushes|40 and 14| ci rotatable arm lil, segment 3 of 30 close Contact 2itransmitter |38, conductor 280, contact |82, ccntact 143, Contactconductor 23, Contact 23.5, top winding of reay S and sistance 221 toground. The armature oi relay is actuated to The armature ci `polarrelay |23 is actuated to the lett but it is ineffectual at this time.When contact 2 l is closed positive pulse is impressed on conductor il.st positive pulse continues as long as Contact 223 remains closed. Whencam 229 has rotated so that its follower engages the depressed port-ionof cam 22S, contact 223 opens, the top windings of relays 288 and |26are deenergized, the armature ci relay 20B is operated into engagementwith Contact li.

@Ground is connected through contacts 2i3 and battery each followed by ashort grounded interval are transmitted through contacts i 0 and E i5respectively. In response to successive pulses oi positive battery thesix-pulse selector which is well known in the art, closes Contact 2"".This establishes a circuit from positive battery' through contact 25|and the winding of relay 252 to ground, operating relay 252. The closingof col.- tact 253 establishes a circuit from battery through contact 264in the six-space selector Contact 253 and the winding of relay 252 toground to maintain relay 252 operated. Relay 252 will remain locked inthe operated position until the transmission from Fig. l is terminatedwhen the six-space selector will be operated by the transmission of atrain of at least six-spacing or ground pulses to open contact 255|.This will be described more fully hereunder.

Contacts 251i and 220 through which receiver 22| was connected to thecable circuit are nov; opened from the operation of relay 252 andcontacts 255 and 255 are closed. A circuit may then be traced from thearmature of relay .l through contact 258, contact 253, and conductor 259through the top winding or" relay 38| to ground. A circuit may also betraced from Contact 260 of relay '25? through contact conductor 2% i,and the top winding of relay 332 to ground. The circuit is now incondition to direct impuls transmitted over cable 2id through regent iverc pcater 219, and contacts 55 and 2 5 to polarized receiving relays 35|3522 of Fig. 3. Thearmatures 'of relays 35i and 362 are normallyVactuated to their right-hand positions under the influence of :currentflowing through their biasing circuits which may be traced from negativebattery through the bottom winding of relay 35| and the bottom windingof relay 3W to positive battery. As positive battery is connected tocontact 25S andcontact 255i through the operation of polar relay 251 ofregenerative repeater 2id in response to the positive and negativeimpulses received over the cable, the armatures or" relays 36| and 362will be actuated to their left-hand positions. In response to a groundsignal element, as distingus ed from curbing ground, contacts 258 and259 will both be en and the armatures of relays 3U! and 302 will both beactuated to the right. The cable code regenerative repeater whichreceives the cable code signals to perform these functions together withthe six-pulse and sixspace selectors are all Well known in the art andWill not therefore be described in detail herein.

To return noW to Fig. l. After the six or more switching pulses havebeen transmitted over cable 2|8, relay H5 will be sufficientlydeenergized so that contact Ht will close. On the next closure ofContact |21 when 229 causes an opening of Contact 223, a circuit maythen be traced from Y ground through contact tit, contact |21, arma-1 4the circuit which has been traced from battery 222 in Fig. 2 to ring |35is extended through brushes il! and 55|, segment conductor |19, Contactitil, conductor i2, contact 235i, top 7vinding of relay 223.8 andresistance to ground operating the armature of relay 255 to the left.This transmits a negative battery over cable 2H to start distributors352 and tilt in a manner to be described below.

TheL transmitting and curbing cam 229 in the present embodiment isfork-driven at a speed of y,

140 revolutions per minute. The transmitting distributor |38 is drivenat a speed of 150 revolutions per minute. The difference in operatingspeeds of the two transmitting mechanisms is adjusted by arresting therotation of rotatable arm |31, once in each revolution. The stop Cam isarranged so that arm |31 is stopped approximately in the position shownnear the righthand end of segment 3 of the distributor. Once startmagnet l1 is energized and the right-hand end of lever H8 is disengagedfrom shoulder |25) of stop cam 12| shaft |22 cannot be arrested untilshoulder |2ii of stop cam |2I' is in position to reengage the right-handend of lever H8. To anticipate, the armature of relay |26 will beactuated to Jrhe left to disengage from contact |21 during the firstthree-quarters of each rotation of cam 229. This opens the circuit ofmagnet H1 and the right-hand end of lever H8 is interposed in the pathof the shoulder |20 of cam V|2i under the influence of spring H9 oncefor each signal element transmitted. However, this is ineffective untilthe shoulder |23 has rotated into the stop position near the end of thethird pulse. When the third pulse is being transmitted and the armatureof 'relay |26 is actuated to the A left, start'magnet ||1 Willberdeenergized and yin the raising of the right-hand end of the leverwill be eiective to arrest the rotation of the arm |31 of thetransmitter distributor |38. As cam 22s continues its rotation Contact223 is opened, the top Winding of relay |26 is deenergized, theoperating path for start magnet ||1 is reestablished, lever H8 isdisengaged from shoulder |20, and the rotation of shaft |31 resumes. Therotation of the shaft will be arrested once in each revolution and thedelay interposed will be just suilicient to compensate for thedifference in operating speeds 'of the tWo mechanisms.

Teletypewriter station |55 which is remote from the transmitting codetranslator is connected by means of conductors |5| and |52 to the typingreperforator |38. As the teletypewriter contacts |53 are operatedlive-element current and rio-current pulses are transmitted over acircuit which extends from the negative terminal of battery i5@ throughbreak key |55, teletypeW-riter transmitting contacts |53, receivingmagnet |56, conductor l5|, reperiorator magnet |51 and conductor l 52 tothe positive terminal of battery |54. :In the present embodiment of theinvention the dye-element current and rio-current signals aretransmitted Yfrom the teletypewriter to define each character at therate of 60 Words per minute. The transmitter distributor transmits thecable code combination at a speed of 23.4 Words per minute. While theteletypewriter is operating, tape will accumulate. Each character isdeiined in the tape 01 as a combination of five '.35 perforated orunperforated elements arranged transversely in tape |51. The tape is fedinto the transmitting distributor and interposed between pins |53 and|62 and their respective contacts 453 to |51, inclusive, in a Well-knownmanner.

:40 Where an element in the tape is punched the corresponding contact isclosed and where an element is unpunched the corresponding contact isopen.

When contact itt is closed a circuit may be traced from positive batterythrough sensing rpin 58, contact I 63, and the Winding of relay |68,loperating relay 62. When contact |64 is closed a circuit may be tracedfrom positive battery through sensing Jin |59, contact |55, and thewinding of relay |69 to ground, operating relay M59.. When contact |65isv closed a circuit may be traced from positive battery through sensingpin |50, contact |65, and the Winding of relay HE to ground, operatingrelay |10. When contact it is closed a circuit may be traced frompositive battery through sensing pin |5|, contact it, left-hand Windingof relay |12 and, when contact |13 is closed, to ground through contact13, operating relay |12. When contact |61 is closed a circuit may betraced from positive battery through sensing pin |52, contact |61,lefthand Winding of relay |1| and, when contact |13 is closed, throughcontact |13 to ground, operating relay 11|. When Contacts |53 to |51 areopen the corresponding relay of the group I 58 to |12 will not operate.

The tape is drawn into position so that all of the punched and unpunchedareas in a particular transverse section representing a particularsymbol are sensed simultaneously by pins |58 to |62. The pins areWithdrawn While the third pulse i-s being transmitted and the succeedingtransverse tape section identifying the nest character is moved intoposition so that the elements may be sensed by the pins before rotatablearm |31 sweeps onto segment I. Elements i, 2 and 3 in the tape controlrelays |68, |69 and F1o. These relays cooperate as a group. It will bemade apparent below that when the rst element of the four-element codeis transmitted the circuit extends from the transmitting cam 229 throughsegment I of transmitter |38 through a path which when closed extendsthrough a combination of the contacts of relays |68, |69 and |18 toeither conductor I I2 or I I3 which controls relays 298 or 289 so as totransmit either positive battery or negative battery. If the paththrough the contacts of relays |68, |69 or |10 is open relays 208 and299 connect ground to the cable for the particular signal element. Whenrotatable arm |31 sweeps onto segment 2 of distributor |38 the pathextends from transmitting cam 229 through segment 2 of distributor |38and through a certain combination of the contacts of relays |68 to |19to conductor |I2 or I|3 to control relays 208 and 299 so as to transmiteither a positive or negative pulse or, if the path through the contactsis open, ground as the second element of the four-element cable code.Thus the first three elements of the ve-element code control relays |68to |10 in a manner to produce two signal elements each of which may beof any one of three conditions depending upon the settings of relays |68to |19. The fourth and fifth elements of the live-element code set thearmatures of relays |1| and |12 which cooperate also to establishvarious combinations of closed paths or open circuits through thecontacts of these re lays in tandem to conductors I2 and I I3 and relays298 and 299. When rotatable brush arm |31 sweeps onto distributorsegment 3 the circuit from the transmitting cam 229 will be extendedthrough various combinations of the contacts of relays |1I and |12 intandem t0 conductor II2 or I I9 to control the settings of relays 208and 209. Positive or negative battery or ground will be transmitted forthe third pulse of the fourelement cable code. When rotatable brush arm|31 sweeps onto contact 4 of transmitting distributor |38 the circuitfrom transmitting cam 229 will be extended through various combinationsof closed or open circuit paths through the contacts of relays |'1| and|12 in tandem to conductors ||2 or |I3 to control relays 208 and 299 soas to transmit either positive or negative battery or ground as thefourth pulse of the cable code combination.

The transmitting tape as has been explained is presented to the sensingpins so that all five elements in the tape may be sensed at the sametime. Relays |98, 189 and |19 corresponding to the first three elementsof the five-element code are controlled substantially instantaneously,as soon as the pins are set in position and remain under direct controlof the sensing pin contacts only, as the pins remain in their selectedpositions throughout the entire interval while the nrst two cable codeelements, into which the first three elements of the five-element codeare translated, are being transmitted. In tracing the operating circuitsfor relays ill and |12 which cooperate to determine the nature of thethird and fourth elements of the four-element code, it was pointed outthat in order to operate relays I1| or |12 contact |13 must be closed.Relays |1| and |12 cannot be operated until relay |25 is released toClose contact |13. After the No 4 pulse of the preceding four-elementcombination is sent, contact |23 is opened. Relay |25 releases andrelays |1I and |12 are set in whatever position is necessa-ry inaccordance with the fourth and fifth elements of the tape codecombination which is presently being transmitted. Contact |23 is openedafter the fourth signal element of the four-element code for thepreceding character is sent. Relay |25 releases closing contact |13.Relays I'Ii and |12 are operated or remain released in accordance withthe fourth and fifth elements of the live-element code. The sensing pinsare withdrawn while the third element of the four-element code is beingtransmitted. But before the pins are withdrawn, relay |25 is againoperated to establish a locking circuit for relays |1| and i12. Thelocking path extends from battery through Contact |16 and the right-handwindings oi' relays |11 and |12 in parallel to ground. Contact il closesbefore contact |13 opens. Thus even though the sensing pins arewithdrawn before the transmission of the third element of thefour-element code is completed, the paths through the translator circuitwhich determine the nature of the third and fourth pulse of thefour-element code are maintained until the transmission of the third andfourth element is completed.

Refer now to Fig. 4. In the code tabulation per Fig. 4 at the upper leftis shown a code tabulation entitled 5 Unit and at the upper right a codetabulation entitled 4 Unit. In the 5 Unit tabulation there are threevertical columns of -land symbols. In the 4 Unit tabulation there aretwo vertical columns of J.- and 0 symbols. The group of symbols in eachhorizontal line of the upper left-hand vertical tabulation correspondsto a different combination of the rst three elements of a five-elementcode. There are eight possible combinations of -land symbols that can oeformed out of three elements each of which may be or The 4 Unittabulation shows, on a corresponding horizontal line, the twothree-element symbols of the 4 Unit code into which the threetwo-element symbols of the 5 Unit code are translated in the inventionherein. At the lower left of Fig. 4 is shown a code tabulation having aheading 4 5 and at the lower right is shown a code tabulation having aheading 3 4. The heading 4 5 represents the fourth and fifth elements ofthe live-element code. The heading 3 4 represents the third and fourthelements of the 4 Unit code. Under the heading 4 5 are shown the fourpossible different combinations of -land elements corresponding to thefourth and fth elements of the 5 Unit code. On a correspondinghorizontal line under the heading 3 4 are shown the symbols in the 4Unit code into which the fourth and fifth elements of the 5 Unit codeare translated. Attention is called to the fact that in the 5 Unit codethere are but two kinds of symbols, viz., -land representing the currentand rio-current condition of each of the five elements of thefiveelement code. 'Under the 4 Unit code there are three kinds ofsymbols, viz., -l-, and 0. -lstands for positive battery, representsnegative battery, and 0 represents ground on the 4 Unit cable code.

The various paths through the five to fourelement relay translator shownin Fig. 1 for the code translations indicated in Fig. 4 will now betraced.

First, the translation indicated in the top horizontal line, that is.the translation from three elements in the five-element two-conditioncode to a -l and element in the four-element three-condition code willbe described.

For the'three -ielements relays |63, |69 and 10 are operated asdescribed. When contact 223 is closed a circuit may be traced frombattery 222, through contact 223, contact 233, conductor top winding ofrelay |26, solid conducting ring |39 of distributor |38, conductingbrushes |40 and iti of rotatable arm |37 of distributor |38, c011-ducting segment l of distributor |38, conductor Iii, contact i! of relay|88, contact |82 of relay 59, conductor H3, contact 235 of relay 230,top winding'of relay 208 and resistance 221 to ground, operating thearmaturev of relay 208 to close its contact Zit. The path through thetop winding of relay 209 is open. The armature of relay 209 is inengagement with contact 2|3 under the influence of current owing throughits bottom or biasing winding. When contact 2 5 is opened the positionof the armature of relay 209 does not aiect the signal elementtransmitted. Positive battery 228 is connected to cable conductor 2 bythe armature of relay 208 as the rst signal element of the four-elementthree-condition code. The positive pulse continues until transmittingand curbing cam 229 has rotated into position to open contact 223. Thenthe top winding of relay 258 is deenergized. The armature of relay 20Sis actuated to close contact 2|5 under the influence of current flowingin the bottom or biasing winding of relay 208. Ground for curbing ordischarging the cable conductor is connected to conductor 2|? over acircuit which extends through contact 2|3, armature oi relay 209,contact 2|5 and the armature of relay 208 to conductor 2 I It is pointedout that the portion of the transmitting circuit extending from battery222 to the conducting brush |4| of distributor |38 remains unchanged forthe transmission of each signal element of the four-element code. In thedescription below the transmission path between battery 222 and brush|4| will therefore not be retraced.

When brush |4| sweeps onto segment 2 of distributor V58 the transmissionpath is extended through conductor |78, contact |83 of relay |68,contact |84 of relay |69, contact |85 of relay |10, conductor H2,contact 234 of relay 230, top Winding of relay 209 and resistance 240 toground actuating the armature of relay 209 to engage contact 2M. Theposition of the armature of relay 208l remains unchanged. A circuit maythen be traced from negative battery 226, contact 2|4, armature of relay209, contact 2|5 and the armature'of relay 208 to cable conductor 2|'|.Negative battery is thus connected to the cable as the second element ofthe four-element code.

Attention is called to the fact that when the transmission path frombattery 222 extends through conductor H3, positive battery is connectedto cable conductor 2|'| and when the transmission path from battery 222extends through conductor 2 negative battery is connected to cableconductor 2|'|. Attention is also called to the fact that if battery 222is not connected to either conductor 2 o r H3, the armatures of relays208 and 209 are both actuated to engage their respective right-handcontacts, under the influence of their respective bottom or rbiasingwindings. Under this condition ground is connected, as has been shown,to conductor 2H. Ground as has been explained is connected to cable 2|?for two conditions, namely for curbing and also for the transmission ofthe kthird of the three signaling conditions for any one of the fourelements of `the four-element cable code.

In the followim;` description only that portion of the transmittingpath' extending between brush l! and conductor |612 or H3 will vbetraced. When the path extends to conductor H3 a positive signal elementwill be transmitted over ycon-- ductor 2|'|. When 'the path extends toconductor i l2 a negative signalv element will be transmitted overconductor 2H; When the path is not continuous to either conductor H2 orH3 the top windings of both relays 208 and 209 will lbe deenergized. Thearmatures of relays 208'and 209 will both be actuated to engage theirright-hand contacts and ground will be connected'through contacts 2i3and 2i5 to conductor 2H;

Now the translation indicated in the toip horizontal line of the bottomleftand right-hand tabulation under the headings 4 5 and 3 4 will beexplained. ln this translation the fourth and fifth elements of thelive-unit code are translated into the third and fourth elements of thefour-unit code.

As explained above, the -fsymbol for the fourth element in thefive-element code indicatesy the relay |72 is operated. The symbol forthe fth element of the live-element code indicates that relay l'll isreleased.

For this condition when brush |45 sweeps onto segmentl 3 a circuit .isestablished which extends through conductor |88, contact 1420i relay21|, contact |86 of relay liz-and contact |31 of relay |12 toconductorH3. This eiects the transmission of a -lpulse as the third element ofthe four-element code.

When brush |4| sweeps onto segment 4 a circuit is established whichextends through conductor |79 and Contact |88 of relay to conductor H2.This eiects thetransmission of a pulse for the fourth element of thefour-element 40 code.

Thus a live-element code consistingof the ve elements -iis translatedinto a fourelement code consisting of the four elements -l- The pathsthrough the relay code translator of Fig. i for the translation of theseven other pos'- sible permutations of elements 1, 2 and 3 of thefive-element two-condition code into corresponding elements and 2 of thefour-element threecondition code, indicated in horizontal lines two toeight in the upper portion of Fig. 4, under the headings 5 Unit 1 2 3and e Unit 1 2 will now be traced. Thereafter the paths for thetranslation of the three other possible permutations of elements 3 and eof the ve-element two-'condition code into corresponding elements 3 and4 of the four-element three-condition code shown in the bottom threehorizontal lines in the lower portion of Fig. 4, under the headings 4 5and 3 4 will be traced.

The second horizontal line in Fig. 4 shows a group of three elements,viz. In conformance with this grouping, relays |68 and |89 will beoperated and relay i'l will be released. From segment the path extendsthrough conductor |11, contact I8! and contact |82 to conductor l i3.The rst element of the corresponding four-element code will therefore beFrom segment 2 the path extends through conduotor |28, contact |83,contact 84 and contact to conductor l i3. The second element of thecorresponding four-element code will therefore be -I- also.

The three-element combination shown on the 'i3 third line is Forthiscondition relays |38 and 10 Will be operated and relay iBS Will bereleased.

From segment l the path extends through conductor |11, contact .EBI andcontact |9| to conductor I2. The irst four-element pulse is From segment2 the path extends through conductor |18, contact |83, contact |92 andcontact |93 to conductor H2. The second four-element pulse is also.

The combination shown on the fourth line is For this condition relay |68Will be operated. Relays |63 and |10 Will be released. The circuitextends from segment i through conductor |11, contact l8| and contact|9| to conductor ||2. The first impulse of the four-element code istherefore From segment 2 the circuit extends through conductor |13,contact i83 and contact |32 to an open circuit at contact |83. This, ashas been explained, results in the transmission of ground, representedby the symbol as the second impulse of the four-element code.

The iifth line shows the symbols -1, for the uve-element code. Relay |68is released and relays |69 and |13 are operated, The circuit extendsfrom segment l through conductor il?, contact |94, contact |25, andContact |98 to conductor I2. The rst element of the four-element code istherefore `From segment 2 the circuit extends through conductor |18,contact |91, contact les and contact |99 to conductor H3. A pulse istransmitted as the second element of the four-element code.

In accordance with the code for J,- on the sixth line relays |33 and |13are released and relay |39 is operated. From segment the path extendsthrough conductor |11, contact 34, contact |95, and contact 4H toconductor |i3 transmitting a pulse as the irst element or" the corresponding four-element code.

From segment 2 the circuit extends through conductor |18, contact |91and contact |38 to an open circuit at contact leg. Accordingly, groundrepresented by the symbol O is connected to cable conductor 2 |1 for thesecond element of the fourelement code.

In accordance with the code for -lshown on the seventh line, relays E38and |553 are released andrelay 18 is operated. From segment l the pathextends through conductor |11 and contact |96 to open contact |35. Thisconnects ground, represented by the symbol 0, to cable conductor 2|1 asthe first four-element pulse.

From segment 2 the circuit extends through conductor |18, contact |91,contact 48d and contact 68| to conductorl i3. The second four-elen mentpulse is therefore In accordance with the code for shown on the eighthline relays |33, |58 and |18 are released. From segment i the circuitextends through conductor |11 and contact |86 to open contact 95. Groundis therefore connected to cable 2|1 represented by the symbol 0 as thefirst element oi the four-ciernent code.

From segment 2 the path extends through conductor |18, Contact Edi,contact 233i! and contact 402 to conductor ||2. The second four-elementpulse is therefore On Vthe second line under the heading 4-5 the code-lappears. Relay |12 is released and relay |1| is operated. From segment3 the circuit extends through conductor |88, contact 403, conifi tactand contact hifi to conductor H2. The third element of the four-elementcode is therefore From segment 4 the circuit extends through contacti335 to conductor l i3. The corresponding iourth element of thefour-element code is therefore On the third line under the heading 1 -5the symbols appear. Relays iii and |12 are both released ior thiscondition. Frein segment 3 the circuit extends through conductor |83,contact |42, contact M3, contact and resistance its to ground. Contactfit is open. This results in the connection of ground to cable 231represented by the symbol 0 under the heading 3 4 as the third elementof the four--elenient code.

From the fourth segment the circuit extends through conductor i'lzicontact |88 to conductor i i2. The fourth element of the four-elementcode is therefore One the bottom line under the heading 2 5 the symbols-iappear. Relays ill and |12 are both operated for this condition. Fromsegment 3 the circuit extends through conductor E38, contact 463,contact dit, contact sul and resistance |83 to ground. Contact i3d isopen. This results in the connection ol? ground to cable 2|1 representedby the symbol 0 under heading 335 as -the third element oi thefour-element code.

From segment i the circuit extends through conductor |13 and contact 65to conductor ||3. The fourth element of the corresponding fourelementcode is therefore Refer now to Fig. 3.

The four-element receiving distributor 304 in the four-to-five-elernentretranslator and the associated relay circuit, together with thetransmitting distributor 333 for the five-element code made be assumedto be in the condition indicated when the apparatus is idle. Switch 331of Inotor 388 of receiving distributor 331i and switch 325 of motor 325of transmitting distributor Sile are closed manually preparatory tooperating the mechanism oi Fig. 3. Whenever the system per Fig. 1 may beoperated switches 301 and 32S will be closed. Motor 33e rotates, drivingshaft 309. Driven shaft 3|@ is restrained from rotating through frictionclutch 3| i, by the right-hand end of stop lever 3|2 of start magnet3|3, which engages a raised shoulder' SIA on the periphery of stop cam 3l 5 which is rigidly secured to 'transmitter-distributor shaft 3|i.Rigidiy secured to distributor shaft 3 5 is rotatable distributor arm3 1. Secured in arm 3|1 are conducting brush 318 which engages the innersegmented distributor ring and conducting brush Sie which engages theouter segmented distributor ring. Driven shaft 318 is coupled totransmitter shaft 346 by worm 32e which is rigidly secured to shaft 3l@and spur gear 32| which is rigidly secured to shaft Siti.

The rotating arm 3 i 1 is arranged to be arrested in the positionindicated with brush SIS engaging segment 321 and brush SiS engagingsegment 328.

The operation of the driving mechanism oi transmitting distributor S issubstantially the same as that or receiving distributor 383 except thatthe outer conducting brush 33t is always arrested when it engages stopsegment 33 l.

Attention is called to the fact that the outer ring of distributor 363has four segments spaced and of a size to receive the center portiononly of the four signal elements of the four-element code. These foursegments 352, 368, 336 and 592 are relatively short.

In response to the reception of the negative :starting impulse, thearmature ofi'el'ay :33| is actuated to engage contact' 353.A'cireuitinay now be traced from negative battery through contact 35S,resistance 334, conductor 335, segmentl32i, brush Sits, brush3i9,segment`r328. conn s 4ductor 335, windingof relay 331, contact relay 339and contact 343 of relay SISI 13o-ground -operating relay 331. rIheoperationof'relaySS establishes a circuit fromzbattery through icontact342 of relay 331, conductor 353 andthe Wind- --ing of start magnet 3| 3to ground. Theletehand -end of stop lever 3 l 2 is raised againsttheiniiuence .ofv spring 331i attached tothel right-.hand Yend or" lever3i2. The right-handend of lever .13:'2 is disengaged from shoulder 3Ifi.Rotatablel brush arm Si? of distributor 333 starts.torotateinzaclockwise direction. The closing @contact-i345 of `relay 33? establishesa .circuit 'from "battery `through contact .345 andthe Winding of :startmagnet 346 of the five-element transmittingdistributor 355. Rotatablebrush arm 351 starts to rotate in a clockwise direction.

As brush 3l@ engages segment 532 correspond- -ing to the fourth elementofthe four-element code, relay 393 will not be operated,- since con-Vtact 359 of relay 33t will remain closed'and negative battery connectedto contact 333 'Will voppose negative battery connected to the:right-hand Winding of relay 393.

After the start pulse is received' let itfrbeassumed that thefour-element cable code `con.-

-bination comprising the two elements shcwnon the first line of Fig. 4under the hea'dingfl-i, viz., -iand the two elements shownonthe .rstline under the heading 3-4, viz., areV Vfirst to be received over thecable. Theirstf'two elements -lof the four-element code'iareztdbe'translated into the elements -I- -I- -l-fas the rst three elements ofthe live-element code andthe second pair of elements which are: thethird and fourth elements of the four-element rcode are to be translatedinto the elements -|--11as the fourth and -fifth elements of theJe-element'code.

In other-Words, thefourfelement combination -i- I- is to be translatedinto the fiveeelement When brush 353 engages segment'35,"a circuit rnaybe traced from positive battery* through resistance 34S, segment 333,brushes SIB ands3I-S,

Vsegment 356, conductor 35i/'and the winding-.of

relay 352 to ground operatingrelay352. Relay 352 vis a locking relay,When relay-.352 is-released battery is supplied through'contact '353 tothe left-hand locking windings of relays 354,555,556

and 351. Such of these relays as have been Yoperg ated on the precedingcycle of operations,A in ac cordance with the first tWo elements of thefourelernent cable code, in a manner to .be described hereunder, will belocked through Vcontact 353, 359, 363 or 35i. releases such of theserelays as'havev been'lo'cked in the previous cycle so that relays 354 to351 are conditioned to receive and register thev nature of the rst twosymbolsof the four-elementzcode.

When brush SiS engages segment 1362 the rst.

positive element of the four-.element code Will'be impressed on thetranslating circuit. :The'circuit extends from positive battery throughcontacti332, contact 333, resistance 334, conductor V335,:seg-

ment 321, conductor 333, segmentzl'SEll, brushes f .3I8 and 3m, segment352 and conductor whichconnects in parallel to the right-handr-Wind-'ings of relays 355 and 355 throughfrectiers366 and 361, which areoppositely poled. .RectierfSBB .presents .allow resistance torcurrentiofpositive The opening of Contact `3531 are 'polarityssothat substantialcurrent fiowsthrough i'retieri3S6larrdthe rightlhand winding-ofrelay355i to ground operating relay 354. Rectieri-`351 presentsaanexceedi-ng'lyrhigh 'resistancei--to curfrent for positiverpola'ritysothatthel resistanee'oi the circuit extending :throughv lrectifier 351A. the rights-hand :winding ;.of :relay I.355 ato Nground is:toes-.great to;l permit relay 355i to frbe-:energized. :Contacttherefore closesfandzcontact 353:- remains open. When brush arinSihhasrrotated tintoposition sothat brush; 329 .engagea-segment thesecondi element. ofiw the .fcur-felernentcable code Willbezimpressedonthe` retranslator mech- L.anisrn .Thelsccond---element ris ea* negative;element. vIn response; tothis the-armature ofI relay k.3!! I will-Abe.actuated' to .close contact 1369. l A circuit may then be tracedfroin'negativesbattery through .contact 369,V resistance 4331i,.conductor T335, segmentl, conductor 565,-segment'3i brushes 3 I 8 and-3I 9, segment; 358 .and Iconductor -Sfrcm which .parallelfbranchesextend. -.Qne

the parallelbranches extendsthrcugh rectier "'and the right-handWindingwoi' relayLSSy to ground. The other parallel branch extendsthrough rectifier' 31|.-andfthe righthandwinding of relayr3511to ground..Rectifier319..presentsila very high resistance to currentor negative.polarity so that relay S356 remains unoperated. Rectifier'. 31Lpresents ai lowresistanc'e'lto .current of negative polarity so thatthe. right-.hand Winding of. relay 351is energizedclosing contactl`36 I.

`R`elay"352 Was released whenbrusharm 311 swept beyond segmentl..'Contact353 .was

closed, When relay '354.operated Va. circuit ,was

established frombattery'through contact 353, Contact 35S and theleftehand winding .of relay 354 rto ground`locking.relay"354.'.Whenrelay "S351 was .operated a cir-cuit was. establishedffrom batterythrough contact353, contactl'3Lan'd the `4,0 left-hand Winding ofV relay'351' toigground locking relay v351. "Relays`355 and'irernainediin thereleased condition. Y

.The distant vee'elernent Ateletypevvriterfstation arranged to receive-'ifive-eierrient'two-condition signals is connected to' transmitting'distributor 305 atv the cable receivingV retranslating station bymeans. of aA pair of conductors 552 and "554. While distributor'35 inthestop position shown, printer. magnet 313 Vis energized bycurrent'ilowing over a circuit which extends frorn'the rightfhand.terminal of battery'35, conductor 552, Winding of printer magnet 314,conductor 545,. ring .313,

`so that the gap between inner ring313 Aan'd'segment 316 of `thetransmitting distributor 'is bridged by rbrushes-32S; and'l, aVv circuitmay be traced from the-'right-hand'terminal voi battery '315 throughconductor 552, winding ofe'printer -rnag'net-S, conductor 554, inner'ring 333, seginentf315, conductor "311, rcontact 1318, Contact 313, andconductor 380 to the leftl-hand terminal of ba-tteryll315whichsendsrafcurrentimpulse to the printerCorrespendingl to the--|.symbol show-n in the top line under theiheadingl--Z-S -in Fig. :'75 -4:as the nrstfelementLof @.theriveeelement lfccde.

When brush arm 341vhas rotated into position so that lbrushes 329 and339 bridge the gap between in er ring 313 and segment 39| of thedistributor a circuit may be tracedrfrom the right-hand terminal ofbattery 315 through conductor 552, winding of printer magnet 314,conductor 554, ring 313, brushes 329 and 330, segment 38|, conductor382, contact 383, contact 384,*and conductor 380 to the left-handterminal of battery 315. This transmits another current impulse,represented by the symbol as the second impulse of the ilVe-elementcode.

When brush 330 engages-segment 385 a circuit may be traced from theright-hand terminal of battery 315 through conductor 552, Winding ofprinter magnet 314, conductor 554', ring 313, brushes 329 and 330,segment 395, conductor 336, contact 381, contact 388, and conductor 380to the left-hand terminal of battery 315. This transmits a thirdpositive pulse, represented by the symbol -l, as the third element ofthe veelement code.

Attention is called to the fact that the first two elements of thefour-element code, namely the -lelements, have been translatedinto therst three elements of the five-element code, namely, the -l- -i--lelements.

When brush arm 3|1 of distributor 303 rotates into position so thatbrush 3|9 engages segment 369 a circuit may be traced from batterythrough resistance 399, segment 390, brushes 3|8 and 3|9, segment 389,conductor 390 and the winding of relay 39| to ground operating relay39|. When contact 392 of relay 39| is opened the locking circuit, whichhas 'been maintaining relays 393, 394 and 395 in positions in accordancewith the third and fourth elements of the preceding fourelement codetransmitted over the circuit, is opened andrelays 393, 394 and 395 arereleased to assume positions in accordance with the third and fourthelements of the four-element code presently being transmitted.

The third element of the four-element code is a element. In accordancewith this the armature of relay 302 will 'be operated to close contact332. The armature of relay 30| will be inengagement with contact 333. Acircuit may then be traced from positive battery through contact 332,contact 333, resistance 334, conductor 335, segment 321, brushes 3|8 and3|9, segment 396, and conductor 391 to parallel branches. One parallelbranch extends through rectiiier 398 and the right-hand winding of relay394 to ground. The other parallel branch extends through rectifier 500and the right-hand winding of relay 395 to ground. Rectifier 398 ispoled so as to present low resistance to current of positive polarity.Rectifier 500 is poled so as to present exceedingly high resistance tocurrent of positive polarity. Relay 394 is operated. Relay 395 remainsreleased. When brush 3| 9 sweeps 01T segment 389 the operating circuitof relay 39| is opened. Contact 392 therefore closes. When relay 394operates, therefore, a circuit is established from battery throughcontact 392, contact 50|, and the left-hand winding of relay 394 toground locking relay 394 in the operation position.

The fourth element of the four-element code is a element. In response tothis the armature of relay 30| is actuated to close contact 369. Acircuit may then be traced from negative battery through contact 369,resistance 334, conductor 335,. segment 321, segment 502, conductor 503andv the right-hand winding of relay 393 to negative battery. Attentionis called to the fact that negative battery is connected to both ends ofthis circuit. Relay 393 therefore remains in the released condition asshown. Relays 393, 394' and 395 cooperate to determine the nature of thelast two elements or the fourth and fifth elements of the five-elementcode.

When brush 330 of transmitting distributor 305 engagesv segment 505 acircuit may 'be traced from the right-hand terminal of battery 315through conductor 552, Winding of printer magnet 314, conductor 554,ring 313, brushes 329 and 330, segment 505, conductor 503, contact 501,Contact 508 and conductor 509 to the left-hand terminal of battery 315.This transmits a current pulse, represented by a symbol, as the fourthelement of the five-element code.

When brush 330 engages segment 5|9 a circuit may be traced from theright-hand terminal of battery 315 through conductor 552, Winding of theprinter magnet 314, conductor 554, ring 313, brushes 329 and 330,segment 5|0 and conductor 5|| to contact 5|2 which is open. As a resultof this negative current pulse, represented by the symbol is transmittedto the printer as the iiffth element of the live-element code.

When brush 330 engages segment 33|, the rotation of the distributor arm341 is stopped. For this condition, the circuit through the Winding o ofthe printer magnet is again closed over a circuit heretofore traced.

From the foregoing it should be apparent that when the iirst element ofthe four-element cable code is positive, relay 354 is operated and relay5 355 is released. When the rst element is negative, relay 355 isoperated and relayr354 is released. When the second element of thefour-element cable code is positive, relay 356 is operated and relay 351is released. When the second ele- 40 ment is negative, relay 351 isoperated and relay 356 is released. When the third element of thefour-element cable code is positive, relay 304 is operated and relay 395is released. When the third element is negative, relay 395 is operatedand relay 394 is released. When the fourth element of the four-elementcable code is positive, relay 393 is operated. When it is negative,relay 393 is released.

The manner in which the first and second elements of the four-elementcable code shown on lines 2 to 8 under the heading 1 2 in Fig. 4 aretranslated into the three symbols for the first, second and thirdelements of the five-element Vcode shown on the corresponding linesunder the heading l-2--3 of Fig. 4 will now be described.

Elementsl and 2 of the four-element code shown on the second line are-l- For this condition relays 354 and 358 Will now be operated. Relays355 and 351 Will be released. For the first eement of the ve-elementcode, a circuit extends from the right-hand terminal of battery 315through conductor 552, winding of printer magnet 314, conductor 554,solid conducting ring 313, brushes 329 and 330, segment 316, conductor311, contact 5|8, contact 384 and conductor 380 to the left-handterminal of battery 315. The circuit is continuous. A current pulserepresented by the symbol will, therefore, be transmitted as the firstelement of the ve-element code. For the second element, a circuit may betraced from the right-hand terminal of battery 315 through conductor552, winding of printer magnet 314, conductor 554, ring 313, brushes 329and 330, segment 38|, conductor 382, contact 5|9,contact 388 andconductor 380 to the left-hand terminal of choosen@ battery V3115.The/second symbol =wil1, therefore,

from `the -rig'hthand terminal of battery 31?? through conductor-552f-Winding of "printer magnet 3M, lconduc'ztorf55e',fring373,bru`she`s 329oan'd 335, segment '385, 'conductor '1386, `contact'52B and contact 52! to Contact cwhichis'open. AJ.Since the circuit toAthe left'hani terminaleoflbattery '.'iis not continuous,anoecurrentpulserepresented-by the symbol willsbe'transniitted as-thethird element of theve-elernentcode.

On vthethird line under vheading 1--2 -of the four-,element code thesymoolsappeain For ths'condition relays 35 andi'! -Will vhe 'operated.lRelays 354 'ands willberelea'se'd. 'Attention'is called tothe-'factthat' the fcircuitlforfthe printer magnet "entends r`always ffrom theVrifgfhthand terminal of "battery i315' through'con-ductor 552, -Winding*of "printer 'magnet 3M, f conductor 5ML-solidconductingrin'g'373,"andbrushes Y"329 s.;

and 33o to someone-ofthe segmentsonthes'outer ring oidistrihutor 3BE.jIn'trac'zingithecircuitsffor vthe remainder of the translations, in"orderito avoid` unnecessary ='repetition `the descriptionhereunder;only thatportionofithe circuit beyond the particular segmentenga-gedbybrush l-i'will be'traced. YWhenhrushfifltengagessegment 315,the circuit `extends through conductor l STI, contact '5 i E5,`Vcontact; "5ivand conductor 3351 Lto .the left-hand Lterminal Vof'battery 375. .A -l pulse will, therefore, be transmitted tothe'rstelement. From' segment 38 Lia-circuit extendsV` through conductor2382 and Ucontact i383to'contact38ll Vwhich is` open ,at 'this ztime.A-:no ecurrentpulsefrepresentedby the symbol-,iwil1,"thereore,`ibe'trans- Initted jas' the second element of *the4fiveselenien't code. 'From' contactt' acirCuitextends throughconch/actor `w3815, Contact 522,'*contact1523and 'conductor 1385 to Lthe"leftfh'and-terminal of *battery 315. "A Vv-l- Vpulse Will,l therefore,)be transmitted asathird-element of the iiVe-'element code.

On the fourth lline underitheheading 41-7-2 of thefoureuntecode,thesyinbols Q appear. -Relay 35'5'Wll-be operatedhyjthe -rpu'lselhearman ward the right fcrthe zeropulse. .Relays `35Saird S5?wilL'thereiore; both bec'reieas'ed. "From/seg,- ment Slt the circuitextends through "conductor 3E?, contactiili, 'contact525,;contact5zp'and'oonuctor 'Sett to "the left-"handterminal :of .vbattery `-325. This resiilts. in a currentplse,.represented the' symbol-lthe' first. element of itheiveelement code. From segment '38Ifacircu'it extends throughconductor toopencircuits at contacts'383,"5119, 52'! and528. Ano-'current pulse represented-bythe symbolwill. be transmitted asthe second elementof theveeelementnode. =Fromsegment 385 a. circuit extends through; conductor bol -`willbe'transmitte'd asthe .third element of the yfive-element code.

On'the fifth lineunder'the :headingil--12 ofthe `four-unit codethersymbols appear. Forithis condition, "relays 355 vand' `will bejoperated.

Relays 35s and '35? 4willbe-released. Fromseg- -inent'iacircuit'extends:throughonductorf'l and Contact Av-5 i8 'to wvopen'contactl 'The first element of theve-element codeissthereore A currentpulse"representedrbypthesymbol -lwill be"transmitted as't'he secondelement-*'offth'e'iiveelement code. `v:From 'segment 31385 fa Aeli-crut-extends through :conductor 386, L'contact '5529, ^con tact 523A'and"conductor `'38l 'to the lefthand "terminal oil-batteryl. A.currentpulse represented bythe symbol #ieyiill2 bertransrnitted as fthethird element-fofthefveelementfcoiie. i A

VvThesixthdine-under the head-ing'fl-i-2 for-the four-unit code showsthe-combination -i-G. For this condition, -relay' 5`42Wi-ll befoperatedandre lays S55, '6fan`d3`5'i'will befreleased. ='From'-'seg ment 3316vfa circuit Iextends through rconductor Z'rl tof openfcontactsI'on-*relays 2351, `"3% and 355. A l no-z'current f plse represented bythe V'symbol Willf'be transmitted as the rst-'elementof gthecorrespondingfiive-element code. From-segment 3s i facircuitfeiztendsithrougi'rconductoriSleenta'ct 528, v-,contactVS525;'coritzmt f 52 6 'and f conductor current-pulserepresentedbyFthesymbol t{ will be transmitted-asthev` secon'dfelem'ent ofthe'veelement'fcode. -`From-`segment v385 a circuit extends throughconductor 386 to open contactson relays '1357 landrt. IA rio-currentpulse representedfby-'the symbol -Awill,'thereforejbeitransmitted vas?the third/element :of -the 4v-veelen^ient code.

The seventh line under'the' headingll-Zloffthe fourelement-codef'showsthe symbolsiO ,-i- Nas Vthe first f and second -elem'ents of ithefour-element code. @Forl'this condition, relay--S'Siyvillbe op erated.-Relays Ir3551!, l'355and"ibwillbe released. Fromfsegment-'STG-"acircuitsextends through conductor 317 #and contactfl'' to Nopen Contact$385,. LA "no-current igpu'ise represented .by A'the 'symbol Willfbeitransmitted `-as "'thetrs't' element of `the five-element tcode. From`segment "33| a circuit l40 second elementsof"theithree-element code.From segment385 'a ycircuit:extends':through-con'ductor 38B, Contact52B, Contact "521 .contact '522 and conductor "336 toithe llet'hand'terminal 4of battery"35. 'A current ,pulsefrepresented by wthe symbol+lwlillbeitransmitted.as .the third element Lofthe five-element code.

'Gn the A,h-lith line underthey heading Vfoi- I2 7or theV ibmelement 4`code ithesyrbls .0 -sappeaix For thiscondit-ion, relay 35? will, beoperated fand relays 3,554, anfd 56 will he; released. Fromsegmentm'i6-a,ci1'cuitextendsuthroughconductor @Ti @to contacts/i5 t6:and -318 in parallelhoth :of whichieadto openfzcircuits.-rn-rno-.ourrentzpu-lse v represented hy'fthe y.symbol--fwillhetransmitted as the -first ielementtoi theg'iiveeelement icode.

From Vsegmento-8 ha .fc-ircuitvfextends through conductor 332-, andecontactill! tto openoontaots 151,8 'and r3 84.,Azfno+currentpulsesrenresented. iby .the symbol :Willlhe transmittedasithe fseoon'd-felevnient of the .inve-element scode. lFromfseen-ientbranch :which rextends from jfc'ontact`522 "terminates vat Yonenfcontacts'f'z fandfEZS. noe'current pulse represented by .the vsymbol f"Will,

therefore, IV"tre transmitted 'as "the rthird .element of`theiveelem-entfco'de.

The Iman-nei" inwhich frelaysii', '384 andcooperate*toetransiatethethird and fourth 'elements; oftlrejfourY-element .coderintojthefourth 21 under the headings 3-4 and4--5 of Fig. 4 will now be described.

The second line under the heading 3-4 shows the symbols as the third andfourth elements of the four-element code. For this concondition, relays395 and 393 will be operated. Relay 394 will be released. From segment505 a circuit extends through conductor 50S and contact 530 to opencontact 53|. A no--current pulse represented by the symbol will betransmitted as the corresponding fourth element ofthe veelement code.From segment 5|0 a circuit extends through conductor 5||, contact 5|2and conductor 509 to the left-hand terminal of battery 315. A currentpulse represented by the symbol will be transmitted as the iifth element of the five-element code. I

The third line under the heading 3 4 shows the symbols as the third andfourth elements of the four-element code. For this condition, relays393, 394 and 395 will all be released. From segment 505 a circuitextends through conductor 506,'contact 530 and contact 53| to opencontact 532. A no-current pulse represented by the symbol will betransmitted as the fourth element of the five-element code. From segment|0 the circuit extends through conductor 5|| to open contact 5|2. Ano-current pulse represented by the symbol will be transmitted for thecorresponding fth element of the ve-element code.

The last line under the heading 3-4 of the four-element code shows thesymbols 0 -las the third and fourth elements of the four-element code.For this condition, relays 394 and 395 will both be released and relay393 will be operated. From segment 505 a circuit extends throughconductor 506, contact 530, contact 53|, contact 532 and conductor 509to the left-hand terminal of battery 315. A current pulse represented bythe symbol will be transmitted as the fourth element of the five-elementcode. From segment 5|0 a circuit extends through conductor 5| contact5I2 and conductor 509 to the left-hand terminal of battery 315. Acurrent pulse represented by the symbol will be transmitted as thecorresponding element of the five-element code.

Each one of the eight combinations of the rst two elements of thefour-element code may be combined with each one of the four combinationsof the second two elements of the four-element code to providethirty-two different four-element combinations. Each one of thethirty-two different combinations of the four-element code may betranslated into a different one of the thirty-two different possiblecombinations of the rive-element start-stop code as indicated.

It was explained above that when the cable relay transmitter was seizedfor the transmission of signals generated in the system per Fig. l, redlamp 242 was lighted and the cable code tape transmitter 20| wasstopped. The cable code tape transmitter is arranged so that when thestart key |0I in Fig. l is opened, releasing relay 230 of Fig. 2 andreconnecting the tape transmitter 20| to the cable relay transmitter,one or more groups of six successive ground pulses will be transmittedover the cable before the cable code transmitter is restarted manually.Such a combination never occurs in the four-element cable code. Inresponse to this, the six-space selector 210 opens contact 234 in awell-known manner. This releases relay 252 and the circuit of Figs. l, 2and 3 are restored to their original condition.

-What is claimed is: Y

l. In a telegraph system, a source ci thirtytwo, tive-element,two-condition, permutation code, telegraph signal combinations connectedto an electromechanical translator and means in said translator, saidmeans comprising two individual multielement selectors each including aplurality of selectively operable relays, the relays of one oisaidselectors actuable by a given number cf the five elements of said codeand the relays of the other actuable by the remaining elements, saidmeans responsive to the reception ci any one of said signalcombinations, for translating said received combinations into acorresponding particular one of thirty-two four-element, threecondition,permutation code telegraph signal combinations.

2. In a telegraph system, a source of five-element, two-condition,permutation code, telegraph signals connected to an electromechanicaltranslating device, means in said device for translating said signalsinto four-element, three-condition signals said means comprising twoindividual multielement selectors each including a plurality ofselectively operable relays, the relays of one of said selectorsactuable by a given number of the ve elements of said code and therelays of the other actuable by the remaining elements, and means insaid system for retranslating said signals into their original form.

3. A five-element, two condition, start-stop permutation code,Atelegraph signal transmitting station, a four-element, three-condition,cable code, telegraph signal transmitting station, a telegraph channel,automatic means for effectively connecting said channel through saidfour-element station to said rive-element station in tandem, a codeconversion device connected to said channel for converting signalcombinations in accordance with said five-element code intocorresponding signal combinations in accordance with said four-elementcode, means connected to said channel to control the time consumed inthe act of code conversion of each individual combination r and means insaid control means for making each of said converted combinations of thesame duration as'each of said four-element combinations.

4. In a telegraph system, a telegraph channel, a rst transmitting meansconnected to a first end of said channel and a iirst receiving meansconnected to a second end of said channel for transmitting and receivingtelegraph signals in accordance with a first code over said channel, asecondtransmitting means connected to said iirst end of said channel anda second receiving means connected to said second end of said channelfor transmitting and receiving telegraph signals in accordance with asecond code, diilerent from said first code, over said channel andswitching means responsive to particular signals transmitted over saidchannel for switching said 4second end of said channel from one toanother of said receiving means, so as to connect the proper receiver tosaid channel to receive signals of a particular code.

5. In a telegraph system, in combination, a telegraph channel, a firstand a second telegraph signal receiving device, a telegraph signal coderetranslator intermediate said channel and said second device, means fordirecting telegraph communication signals over said channel to saidilrst receiving device at a first time, and means responsive to thetransmission of switching signals over said channel for switching saidchannel from said first receiving device through said retransansa-coi Ylator to said second receiving-device? iat-:aiseeondftime.

w6.1i:v a telegraph system, a itelegraph lsignal code. translator` for.translating 'four-element, three-condition, `permutati'on'code signalcembinaticns into rive-element, Vtwo-condition, permutation code signalcombinations and means Jin said translator vfor translating a subgroupof two signal elements of each of said fou'r-element-'s'ignalcombinations into a subgrup 0f 'three/Signal elements 'of each of saidfive-elements'ignal come b'in'ations. l

` 7. In a telegraph system, al telegraph signal code translator fortranslating live-element, tivocondition, 'permutation code, signalcombinationsin'to four-element, three-'condi'toi'r permutation code,signal combinations, a iirst means in fsaid translator fior translatingthree 'of 'the r'e eleinentsfcsaid yiii/e element signals into two c'f'the elements ofsaid four-element signals and a sec'- 'ond 'means insaid translator for translating :two of' the Velements oi' saidtive-element signals into two o'f the elements of said four-elementsignals.

8.- In a telegraph system, 'a telegraph code translator i'or translatingfour-element, threecondition, permutation'code signals into fve-element,two-condition, permutation code signals, a r'stmeafns in said translatorfor translating two Vofthe elements of 'said four-'element signals intothree of the elements of said five-element signals i [and a second meansin said translator vfor translating two ofthe elementsrof 'saidVfour-element signalsinto two yof the elements Yof saidveelementsignals.

9. In a telegraph system, a -'rst telegraph transmitter, means-in saidtransmitterfor generating-telegraph signals in accordance with a frs'tcode, a 'timing mechanism connected to ksaid transmitter, meansconnected' to said timing mechanism 'for controlling the dura-tionofsigna'l elements in said code, a telegraph channel?, means vvforimpressing said timed signal elements on said channel, a secondtelegraph transmitter, means iii-said 's'econd'transmitte'r for'generating signals in' accordance with a vsecond code, d'iiierent "fromsaid rrst code, `means for' impressing signals in accordance withsaidsecond code 'on said channel and' lmeans -for tim-ing thedura-tionof vthe signal elements 'ofisaid second code 'with said timing mechanismso that they may be transmitted vvthrough facil-ities connected to saidchannel adaptable tothe duration ofj signal elements of said first code.y y

110. .In a telegraph system, a Vtelegraph *transmitter, means in saidtransmitteriortransmitting va tran-ici four signal elements to formafourf elementstart-step permutation 4code signal-comwhich may be of anyone of Vtwo conditions 'anda stop element, s, translatorintermediatesaid transmitter 'andire'ceiven ya telegraph channelinterconnecting said transmitter and vreceiver through translatorandxmeans-fin said translator for translating said four-'element traininto said sevemelernent train.

111. -Acode signal transmission system comprisingme'an's' .for producinga two-element; 'iive-un'it 00de, means Yfr(3fm-VeItI-ig.' thf'ee'Gh0`S`rlt1`Hit'S thereof 15D produce eight cb'i'libl'lt'dhs- 0f `lW'()unitslot a'fthre'e-eiament vicuii-unit code,- meansfOrH-cenvertir'ig'twovother 'units' thereof to pro'- iour Umbmations oftwo: units of therthree element, #four-unit code, means vfor combiningthe eight combinations of two units p'ermutatively with the fourcombinations of the tWo other units to produce thirtyrtivo possible'combinations and iiiean's-'for' i'itil'izinfvr codes of the thirty-two`coinbi-nat'ions ci the three-element, Vfour-unit code to controlsignal-ing apparatus. Y

1h21. AAccade signal transmission system comprising means for producinga two-element, n-unit code, mean-s 'for vconverting (11i-p) chosen unitsther-coito produce (ft-pf2 combinations of two units of `a three-elementkm-'unit code, means for converting p other units ,thereof to produce a'(wherecc does nc-'texceed p2) combi-nations of two unitsof` thethree-element m-unit code, means for combining the (n-fp)2 `combinationsof two units permutatively with thezx combinations of the tivo otherunits to produce a given number ciipcss'ible combinations and means forutilizing the given number vof combinations of the threeelement, m-un'itcode for signaling.

i3'. In a 'telegraph system, a five-'element permutation code telegraphsignal transmitter, connected to a l`telegraph signal code translator,means in said 4translator for translating three vof said inve elementsinto two elements of a fourelement code and means in said translator fortranslating the two remaining elements` of said hveeleinentcode into thetwo remaining elen'rents of' saidffcur-element code. Y

` Y EDWARD F.'WATSON.

REFERENCES CITED fheiollowing references are of record in the nio-oithis patent:

' Umrans'rsrrns PATENTS Number

